Machine for sorting statistical cards



P 1933- T A. THOMAS ET AL 1,926,216

MACHINE FOR SORTING STATISTICAL CARDS Filed Feb. 24 1952 3 Sheets-Sheet 1 FIG] zdmzbm- I. 77/0075; aha/raw)? Sept. 12, 1933. THOMAS 1,926,216

MACHINE FOR SORTING STATISTICAL CARDS Filed Feb. 24, 1932 3 Sheets-Sheet 2 FIG. IA.

Sept. 12, 1933. A. THOMAS ET AL 1,926,216

MACHINE FOR SORTING STATISTICAL CARDS Filed Feb. 24. 193 3 Sheets-Sheet 3 FXG.2.

Patented Sept. 12, 1933 UNITED STATES PATENT OFFICE MACHINE FOR SORTING STATISTICAL CARDS Arthur Mowhray,

Thomas, Waiiington,

Peckham, London,

and Edward England, as-

signors to The Accounting & Tabulating Corporation of Great Britain Limited, London,

England 11 Claims.

This invention relates to machines for sorting statistical cards, and has for its object to provide improved timing gear for controlling the compartments which receive the cards during the sorting operation.

In such sorting machines the cards to be sorted pass through an analyzing device, for example, a sensing pin box, and then pass on to the particular compartment which they are destined to enter.

The passage of a particular card through the pin box selects the particular compartment into which the card is to fall, and since the selection takes place at the moment in which the card is in the pin box, means must be provided for delaying the actual opening of the compartment until the card has had time to travel from the pin box to that compartment. For instance, in one form of machine having twelve compartments these compartments are placed side by side in a row, so that a card destined for the last compartment has to pass over the preceding eleven compartments in order to reach its own particular compartment. Consequently, in such a case the timing means must operate to delay the opening of the last compartment until the card has travelled from the pin box to that compartment.

In sorting machines hitherto proposed timing gear has been provided for achieving this object, and the object of the present invention is to provide an improved form of mechanism for controlling the opening of the compartments.

According to the present invention a sorting machine may comprise means tending to hold all the compartments normally open, latching means normally preventing the opening of any compartment, means controlled from the analyzing device to render said latching means inoperative in respect of a particular compartment, and means for automatically reclosing said compartment after a card has entered it.

Timing gear is also provided by means of which, although the particular latching means which is to be rendered inoperative is selected at the moment in which the card concerned is actually in the pin box, said obstructor is not withdrawn or rendered inoperative until the card reaches the compartment into which it is to be delivered.

Conveniently, each compartment is provided with a flap closing the mouth thereof, and this flap is secured to a shaft projecting through the frame of the machine and carrying on one end an arm tending to be moved by means of a spring into a position in which the flap is open.

This arm is normally held by means of a latch in a position in which the flap is closed, and in this position the arm just clears the high part of a cam with the 10W part of which the arm engages when the flap is open. The cam is rotated at such a speed that if the latch is withdrawn the high part of the cam would operate the arm to close the flap once for each card which passes through the machine. Thus, if the latch is withdrawn the compartment is opened by the spring and closed by the cam each time a card passes through the machine.

Associated with the cam is a device for releasing the latch, and this releasing device is controlled from a particular sensing member in the analyzing device corresponding to the compartment to be controlled by the cam.

When a card bearing a designation corresponding to that of the particular compartment concerned enters the analyzing device, one of the sensing members in said device sets the device for releasing the latch, and timing gear is provided whereby, although the latch releasing device is set while the card is in the analyzing device, the latch is not actually released until the card has reached the compartment destined to receive it.

To this end a trip device may be mounted on a disc for rotation, and the releasing means may be in the form of a setting device for the trip angularly displaced round the disc with respect to the latch to such an extent that the time taken for the trip device to travel round from the setting device to the latch is equal to the time taken by a card in travelling from the analyzing device to the compartment.

Normally the trip device passes clear of both the setting device and the latch, but when a card destined for the particular compartment concerned enters the analyzer, the setting device is projected into the path of the trip and sets it to a position in which it will release the latch in passing. The cam is so placed relatively to the trip that when the latch is released the arm moves into engagement with the lowermost part of the cam contour, thereby opening the compartment. As soon as the card has entered the compartment, the cam will have moved round and pushed the arm out again, thereby closing the compartment, whereupon the latch again holds the arm free of the cam.

The invention may be carried out in various ways, but one construction according thereto is illustrated diagrammatically in the accompanying drawings in which the invention is shown, by way of example, as applied to a statistical card sorting machine of the kind described in British patent specification No. 328,293.

In the drawings:

Fig. 1 is an elevation of the machine;

Fig. 2 illustrates in elevation the timing gear for one sorting compartment;

Fig. 3 is a plan of the timing gear shown in Fig. 2;

Fig. 4 illustrates a device for putting out of action when desired, the mechanism for opening any particular compartment, and

Figs. 5, 6 and 7 show different positions of a delay mechanism associated with the timing gear in order to hold a compartment open for a sufficient time to permit two consecutive cards to enter the compartment.

In the construction illustrated in Fig. 1 the machine comprises a frame 1 including twelve sorting compartments S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11 and S12 of which only three are shown, since the remainder are all alike. At one end of the machine is mounted a card analyzer in the form of a sensing pin box 2 and a card magazine 3. The cards are fed from the magazine 3 to the pin box 2 by means of a picker (not shown) operated by means of an eccentric 4 secured to a shaft 5 and connected to the picker shaft 6 by means of an eccentric rod '7 and a short arm 6.

The pin box contains a plurality of sensing pins indicated at 9 and is reciprocated vertically with respect to the cards by means of an eccentric 10 secured to the shaft 5 and an eccentric rod 11.

As described in the aforesaid British patent specification No. 328,293 the pin box is brought down on to a card and those pins which pass through holes in the card become locked to the pin box and act on plungers (not shown) disposed immediately beneath the pin box, these plungers being connected by Bowden cables 12 to the control mechanism for the sorting compartments.

The foregoing description is given in order that the invention may be clearly understood, and as it related to those parts of the machine which are already known, it is unnecessary to describe these parts in further detail.

In the form of invention now being described, the controlling fiap 13 for each compartment (see Fig. 2) is secured to a spindle 14 projecting through the frame of the machine and carrying on one end an arm 15 tending to be moved into the path of cams 16 formed on a cam disc 16a by means of a spring 17.

The cam disc 16a is carried by a sleeve 16b rotatably mounted on a fixed cross shaft 18 and is driven through a worm wheel 19 also carried by the sleeve 16b and meshing with a worm 20 carried on a driving shaft 21, which also serves to drive the card conveying rollers 22 by means of spiral gears 23.

The arm 15 is normally held out of the path of the cams 16 by means of a latch 24 controlled by a spring 25, and the arrangement of the cams 16 and the speed of rotation of the disc 160. are such that if the latch 24 is withdrawn the arm 15 would follow the cams 16 and would thus be reciprocated by one of the cams 16 at each cycle of the machine, i. e. once for each card which passes through the analyzer.

For constructional reasons, six cams are formed on the disc 16a spaced equally apart, and the disc is, therefore, driven at one-sixth of the speed of the shaft which operates the pin box. Consequently, as the disc rotates a cam 16 is always in readiness to operate the flap operating arm 15 every time a card reaches the compartment with which the cam disc is associated. To reduce wear, the arm 15 is provided with a roll 15a which is engaged by the earns 16. As can be seen from Fig. 1, a cam disc 16a is provided for each compartment, and pivoted on the side of each disc adjacent each of the cam projections is a trip member 26 (see Fig. 2), there being thus six trip members on each disc, each of which is adapted to remain in one or other of two positions under the action of a spring 2'7. In passing from one position to the other, a trip member moves through a dead centre position, and a stop 28 is provided to retain it on the particular side of the dead centre to which it may have been set.

As has already been stated, the depending arm 15 is normally held against the action of its spring 17 by means of the latch 24, in such a position that the flap 13 for the compartment remains closed. When it is desired to open the compartment, the latch 24 is withdrawn from the arm 15 by means of one of the trip members 26 carried on the cam disc 16a in the manner about to be described and the spring 17 thereupon causes the flap to open.

When the trip members are in one of their two positions they project beyond the periphery of the cam disc 16a, and as the disc rotates one or other of the trip members will strike the latch 24 and release it from engagement with the depending flap operating arm 15, thereby permitting the said arm to open the flap under the action of the spring 17. Each trip member 26 is so disposed with relation to its associated cam 16 that when the trip member releases the latch, the roll 15a on the flap operating arm- 15 is opposite the highest portion of the cam disc 16a or the summit of a cam 16. Consequently, at the moment of release of the latch 24, the flap operating arm 15 is lifted slightly from it by the cam 16, so that there is no friction between the latching edges. As the cam disc rotates, the arm 15 moves about its pivot 14 under the control of the cam disc 16a and this movement of the arm 15 raises the flap 13 and therefore opens the compartment to receive a card. The card enters the compartment, but before the following card reaches the compartment, the following cam projection 16 comes round and pushes the operating arm 15 out again in an anti-clockwise direction, thereby closing the flap. When the arm 15 has moved into the flap closing position, it is again held in this position by the latch 24.

In their other position the trip members 26 remain below the periphery of the disc and do not project therefrom so that they do not release the latch 24 as they rotate. Normally the disc 16a rotates and the trip members are in their inoperative position in which they do not project beyond the periphery of the disc 1601., so that the depending flap operating arm 15 is aiways held out of engagement with the cam 16 by means of the latch 24.

In order to move the trip members 26 into the operative position, setting means is provided adjacent the disc 16a. This setting means comprises a plunger 29 (Figs. and 3) adapted to slide in a boss 30 carried on the end of a supporting arm 31 secured to the stationary cross shaft 18 by means of a set screw 32. The plunger 29 is normally maintained out of the path of the trip members 26 by means of a spring 29a located within the boss 30 and is adapted to be moved by means of a bell crank 33 so as to project into the path of the trip members 26 and trip one of them into its operative position. The bell crank 33 is connected to a corresponding plunger beneath the pin box 2 by means of one of the Bowden cables 12.

It will be understood that for every column in the analyzer of the pin box there is a given number of sensing pins, for example 12, and there is therefore, a compartment for each sensing member in the column together with a cam disc 16a and associated mechanism for each compartment. There is, however, only one column of plungers below the pin box and this can be set beneath any desired column of pins. Consequently, the bell crank 33 for any given compartment is connected to the corresponding plunger beneath the pin box, so that if a card having a record such as a perforation in the position 4 in the column under which the plungers are disposed, enters the analyzer, the sensing pin 9 corresponding to the position 4 in that column will depress the corresponding plunger and will actuate the bell crank 33 for compartment S4. The consequent movement of the bell crank 33 projects the setting plunger 29 into the path of the trip member 26.

The angular distance between the trip members 26, the speed of rotation of the disc 16a which carries them, and the time during which the setting plunger 29 is projected into the path of the trip members, are so selected that the plunger only sets one trip member and is withdrawn before the next trip member comes into its path. The trip member, having been set into the operative position, continues rotating with the disc, and on reaching the latch 24 releases it, thereby permitting the flap operating arm 15 to engage with the cam disc 16a and consequently open its flap 13, after which the following cam 16 moves round and pushes the depending arm out again, thereby closing the flap as previously described.

As the disc rotates still further the trip member 26 still remains in the operative position, but before it reaches the latch 24 again it strikes a fixed pin 34 which resets it into its inoperative position.

In order to allow the card time to pass from the pin box to the particular compartment which it is intended to enter, the setting plunger for the trip members 26 is positioned with regard to the latch 24 at such an angle that the time taken for the trip member to rotate after it has been set by the plunger until it reaches the latch 24 is equal to the time taken for the card to pass from the pin box to the particular compartment in question.

Thus, the setting plunger for each compartment is angularly spaced from that for the next compartment in accordance with the distance between the compartments. Thus, the setting plunger for compartment S1 is only displaced by a small angle from its respective latch, while the setting plunger for compartment S2 is displaced by a greater angle, and that for compartment S3 is displaced for a larger angle still, and so on.

If desired, means may be provided for entirely cutting out the operation of any compartment. To this end, as illustrated in Fig. 4, an arm 35 secured to the spindle 14 of the flap operating arm 15 may be locked with the flap in the closed position by means of a latch 36 adapted to be manually controlled by means of a hand lever 37 to which it is connected by means of a link 38. In

this way, one or more of the compartments may be permanently held closed.

Further, if desired, the apparatus according to the invention may be modified to sort into the same compartment one or more perforated follower cards together with a perforated key card. A modification of the controlling mechanism suitable for this purpose is diagrammatically illustrated in Figs. 5, 6 and 7.

In the construction illustrated in these Figures, a delay latch 40 is pivoted to the frame of the machine at 41 and may be caused to engage a projection 39 on the latch 24 when the latter is released by one of the trip members 26.

To this end the latch 40 is provided with a spring 42 which holds it over to the right in Fig. 5 against a stop 43. When the latch 24 is depressed by means of one of the trip members 26, the projection 39 engages under the latch 40 as shown in Fig. 6 so that after the flap has been closed by means of the next following cam 16, the flap will open again since the arm 15 will be free to follow the contour of the cam disc 16a.

The flap will accordingly continue to open each time a card reaches the compartment until the delay latch 40 is released, thereby permitting the latch 24 to hold the arm 15 in the inoperative position again. In this way, when the latch 24 is released, the flap opens and the card enters the compartment, and at each successive opening of the compartment a following card will enter it, whether or not this card is perforated.

In order to release the latch 40 when the desired number of cards has entered the compartment, the latch 40 is provided with a lug 44 which is so positioned that the trip member which has been set by the plunger 29 to release the latch 24, will, after a predetermined interval of time, come round and strike the lug 44, thereby tripping the latch 40 and permitting the latch 24 to re-engage the arm 15.

In the arrangement shown in Figs. 5 to 7, the latch 40 is shown as arranged to permit only one follower card to enter the compartment, since, with this arrangement, the delay latch 40 will be released by the appropriate trip member 26 after the flap has been opened twice. If desired, the delay latch 40 may be modified to make it capable of being released from another position still further round the cam disc, so as to provide for a plurality of follower cards.

The cam discs may be made interchangeable so that any disc may be removed and replaced with another disc permitting a longer or shorter opening period for the flap.

It will be appreciated that the apparatus according to the invention provides a means for positively operating a compartment flap to closed position, and that owing to the fact that the cam discs rotate in the same plane as that in which the flap operating arm turns, the parts of the device occupy a relatively small space and are concentrated substantially in one plane instead of being disposed in two planes as in previous arrangements.

Also, since the cam discs are each mounted on an individual spindle any disc can be removed for replacement or repair without disturbing the remaining discs.

It will be understood that although the invention has been described as including a plurality of compartments, it is also intended to cover a sorting, comparing, or verifying machine having only two compartments, one being for the cards actudisc, an

' before rt c ally required, and the other being a reject compartment.

What we claim i 1. In a machine for sorting statistical record cards, having an analyzing device of which the sensing members selectively control compartments for the reception of the cards, the combination of a flap to each compartment adapted to close the mouth thereof, an operating arm for each flap, means tending to move said arm to hold the flap open, a cam adapted to move said arm to close the flap, a latch normally holding the arm in the position in which the flap is closed, a rotatable disc, a trip member pivoted on said disc, and adapted when on one side of a dead centre position to lie within the circumference of the disc and when on the other side of said dead centre position to project beyond the circumference of the disc, a spring and a stop to retain the trip member on the particular side of the dead centre to which it has been set, a setting device for the trip member, to cause it to project beyond the circumference of the disc, and an operative connection between said setting dc vice and a particular analyzing member in the analyzing device, said setting device being disposed with regard to the latch in such a position. that the trip member after being set, but before reaching the latch, moves for a time equal to the time taken for a card to travel from the analyzing device to the particular compartment concerned.

2. In a machine for sorting "atistical record cards having an analyzing dev cc of which the sensing members selectively control compartments for the reception of he cards, the combination of a flap to each compartment adapted to close the mouth thereof, an operating arm for each means tending to move said arm to hold th flap open, a latch normally holding the arm in he position in which the flap is closed, a rotatable c, a trip in ibcr pivoted on said disc and adapted when on one side of a dead centre position to lie within the circumference of the disc and when on the other side of said dead centre position to project beyond the circumference of the means to retain the trip memher on the particular side of the centre to which it been a setting device for the trip member to cause it to project beyond the operative connection between said setting device and a particular analyzing member in the anaiyzing device, said setting device being disposed with regard to the latch in such a position that the trip member after hing the latch, moves for a time equal to the time taken for a card to travel from the anai zing device to the particular compartment cone "deal, and a cam adapted to move the flap operating arm to close the flap, said cam being so placed with respect to the trip member that when the latch is withdrawn the flap operating arm moves into engagement with the lowest portion of the cam surface thereby opening the flap which is subsequently closed by the cam.

rotatable disc, a trip member pivoted on said oa ers disc and adapted when on one side of a dead centre position to lie within the circumference of the disc and when on the other side of said dead centre position to project beyond the circumferonce of the disc, means to retain the trip member on the particular side of the dead centre to which it has been set, a setting device for the trip member to cause it to project beyond the disc, an operative connection between said setting device and a particular analyzing member in the analyzing device, said setting device being disposed with regard to the latch in such a position that the trip member after being set, but before reaching the latch, moves for a time equal to the time taken for a card to travel from the analyzing device to the particular compartment concerned, a cam adapted to move the flap operating arm to close the flap, said cam being so placed with respect to the trip member that when the latch is withdrawn the flap operating arm moves into en agement with the lowest portion of the cam surface thereby opening the flap which is subsequently closed by the cam, and means for causing the latch to rte-engage the flap operating arm as soon said arm moves into the closed position of the flap.

4. In a machine for sorting statistical record having an analyzing device of which the ing members selectively control compartmei Us for the reception of the cards, the combination of a flap to each compartment adapted to close the mouth thereof, an operating arm for each flap, means tending to move said arm to hold the flap open, a latch normally holding the arm in the position which the flap is closed, a rotatable disc, a trip member pivoted on said disc and adapted when one side of a dead centre position to lie within the circumference of the disc and when on the other side of said dead centre position to project beyond the circumferenceof the disc, means to retain the trip member on the particular side of the dead centre to which it has been set, a setting device for the trip member to cause it to project beyond the disc, an operative connection between said setting device and a particular analyzing member in the analyzing device, said setting device being disposed with regard to the latch in such a position that the trip member after being set, but before reaching the latch, moves for a time equal to the time taken for a card to travel from the analyzing device to the particular compartment concerned, a cam adapted to move the flap operating arm to close the flap, said cam being so placed with respect to the trip member that when the latch is with rawn the flap operating arm moves into engagement with the lowest portion of the cam surface thereby opening the flap which is subsequently closed by the cam, means for closing the compartments after a card has entered, means for delaying the closing of any compartment until a predetermined number of follower cards have entered the compartment after a key card has entered it, and means for causing the latch to re-engage the fiap operating arm as soon as said arm moves into the closed position of the flap.

5. In a machine for sorting statistical record cards, having an analyzing device of which the sensing members selectively control compartments for the reception of the cards, the combination of a flap to each compartment adapted to close the mouth thereof, an operating arm for each flap, means tending to move said arm lo hold the flap open, a cam adapted to move said arm to close the flap, a latch normally holding the arm in the position in which the flap is closed, a rotary releasing device for withdrawing the latch, a setting device for said releasing device, an operative connection between said setting device and a particular analyzing member in the analyzing device, said setting device being dis posed with regard to the latch in such a position that the releasing device, after being set, but before reaching the latch, moves for a time equal to the time taken for a card to travel from the analyzing device to the particular compartment concerned, and a delay latch adapted to engage with and hold the latch for the flap operating arm when said second mentioned latch is released, said delay latch being so placed as to be engaged and released by the setting device after the completion of a predetermined number of card cycles from the time when the latch for the flap operating arm was released.

6. In a machine for sorting statistical record cards having an analyzing device of which the sensing members selectively control compartments for the reception of the cards, the combination of a flap to each compartment adapted to close the mouth thereof, an operating arm for each flap, means tending to move said arm to hold the flap open, a latch normally holding the arm in the position in which the flap is closed, a rotatable disc having a plurality of equally spaced cam projections formed on its periphery and adapted to move to closed position the flap operating arm, a corresponding plurality of trip members pivoted to the disc, one trip member associated with each cam projection, each of said trip members being adapted when on one side of a dead centre position to lie within the circum ference of the disc and when on the other side of said dead centre position to project beyond the circumference of the disc, a setting device for the trip members, an operative connection between said setting device and a particular analyzing member in the analyzing device whereby when said analyzing member reads a hole in a card the setting device is projected into and withdrawn from the path of the trip members, thus setting one trip member only, said setting device being disposed with regard to the latch in such a position that the trip member after being set moves for a time equal to the time taken for a card to travel from the analyzing device to the particular compartment concerned, and the trip members being also so disposed with regard to their associated cam projections that when the latch is withdrawn the flap operating member moves into engagement with the lowest part of the cam disc thereby opening the fiap which is closed by the next following cam projection, means tending to cause the latch to re-engage the flap operating arm as soon as said arm moves into the closed position of the flap, and a delay latch adapted to engage with and hold the latch for the flap operating arm when said second mentioned latch is withdrawn, said delay latch being so placed as to be engaged and withdrawn by the set trip member after the completion of a predetermined number of card cycles from the time when the latch for the flap operating arm was withdrawn.

7. In a machine for sorting statistical record cards having an analyzing device of which the sensing members selectively control compartments for the reception of the cards, the combination of a flap to each compartment adapted to close the mouth thereof, an operating arm for each flap, means tending to move said arm to hold the flap open, a latch normally holding the arm in the position in which the flap is closed, a rotatable disc having a plurality of equally spaced cam projections formed on its periphery and adapted to move to closed position the flap operating arm, a corresponding pluraiity of trip members pivoted to the disc, one trip member associated with each cam projection, each of said trip members being adapted when on one side of a dead centre position to lie within the circumference of the disc and when on the other side of said dead centre position to project beyond the circumference of the disc, a setting device for the trip members, an operative connection between said setting device and a particular analyzing member in the analyzing device, whereby when said analyzing member reads a hole in a card the setting device is projected into and withdrawn from the path of the trip members, thus setting one trip member only, said setting device being disposed with regard to the latch in such a position that the trip member after being set moves for a time equal to the time taken for a card to travel from the analyzing device to the particular compartment concerned and the trip members being also so disposed with regard to their associated cam projections that when the latch is withdrawn the flap operating member moves into engagement with the lowest part of the cam disc thereby opening the flap which is closed by the next following cam projection, means tending to cause the latch to re-engage the flap operating arm as soon as said arm moves into the closed position of the flap, a delay latch disposed adjacent to the latch for the flap operating arm and adapted to engage with and hold the said second mentioned latch in the withdrawn position, a releasing device for the delay latch and an operative connection between the releasing device and the delay latch, said releasing device being disposed in the path of the set trip member at a point round the circumference of the cam disc spaced from the delay latch a distance proportional to a plurality of card cycles, whereby the delay latch is released after a predetermined number of card cycles has been completed.

8. A machine according to claim 2, for sorting statistical cards including means for cutting out of operation at will the controlling mechanism for any individual compartment whereby said compartment remains closed.

9. In a machine for sorting statistical record cards having an analyzing device of which the sensing members selectively control compartments for the reception of the cards, the combination of a flap to each compartment adapted to close the mouth thereof, an operating arm for each flap, means tending to move said arm to hold the flap open, a latch normally holding the arm in the position in which the flap is closed, a rotatable disc, a trip member pivoted on said disc and adapted when on one side of a dead centre position to lie within the circumference of the disc and when on the other side of said dead centre position to project beyond the circumference of the disc, means to retain the trip member on the particular side of the dead centre to which it has been set, a setting device for the trip member to cause it to project beyond the disc, an operative connection between said setting device and a particular analyzing member in the analyzing device, said setting device being disposed with regard to the latch in such a position that the trip member after being set, but before reaching the latch, moves for a time equal to the time taken for a card to travel from the analyzing device to the particular compartment concerned, a cam adapted to move the flap operating arm to close the flap, said cam being so placed with respect to the trip member that when the latch is Withdrawn the flap operating arm moves into engagement with the lowest portion of the cam surface thereby opening the flap which is subsequently closed by the cam, a locking lever secured to the flap operating arm and a manually controllable latch adapted to engage with the locking lever and hold the flap operating arm in the closed position of the flap.

10. In a rotatable cam disc for statistical card sorting machines having a plurality of compartments, a closure flap to each compartment, means tending to open said flaps and devices normally holding the flaps closed, the combination of a plurality of settable trip members carried on the disc at equal distances apart and a corresponding plurality of cam projections formed on the periphery of the disc, said trip members and cam projections being so positioned that after being set a trip member engages and releases the associated compartment flap and the next following cam member acts to close said flap.

11. A rotatable cam disc according to claim 10 wherein the trip members are pivoted near the periphery of the disc and are adapted when on one side of a dead centre position to lie within the circumference of the disc and when on the other side of said dead centre position to project beyond the circumference of the disc.

ARTHUR THOMAS. EDWARD MOWBRAY. 

